Well, I've had this thing for a while now, might as well post it on here and maybe get some thoughts/opinions.

In its present state:

I purchased the bike from an Iranian immigrant in Florida who found most of the parts for the bike there and apparently found a very skilled panel beater/metal worker to repair/fabricate all of the sheetmetal. It is 95% complete and missing only the fork trees and linkage, exhaust, gauges, and little obscure bits like the toolbox light, controls and oil pressure button. I'm also trying to find a suitable piston.

Currently, I am considering simply rebuilding the motor and putting the bike together in its present state without extensive painting or plating. I just want to ride the thing.

That is cool! Have you been taking any other pictures of the bits before you started assembling them loosely? I love those pix where all the parts are laid out on shop floors or driveways, then contrast with the gorgeous gleaming finished bike.

P.S. where is that new BSA in your signature lineup? Oh, and thanx for the "tip". I don't get many of those.

GrandPaul (does not use emoticons)Author of the book "Old Bikes"Too many bikes to list, mostly Triumph & Norton, some BSA & European"The Iron in your blood should be Vintage"

Even if you didn't use the original sheet metal, that's a cool machine. Unless you've got deep pockets, skip the chrome & fancy paint. Build a a lightweight machine...pure function. Venolia should be able to make a piston.

Alex , I dont know how you do it ! If that thing was a twin it just might , maybe , out COOL the plunger A-10 . I'm seein a lotta work and parts fabbin/scroungin in your future. Thanks for postin that , it makes me feel like my "modern" stuff should be able to put itself together . Really good to see the actual vintage stuff getting some much deserved attention these days , several being posted here recently .

Alex,Now that i think about it, I may have a complete top end for your bike. My father was rebuilding a ZB goldie when it was discovered that the left case could not be repaired soon enough to go racing.A freshly rebuilt xb motor was purchased for a donor left side case so I have a head, barrel. valves,piston,push rod tube. If these are the right parts and you want to come get it and it solves your problems,it is yours. I would be glad to help.Let me know.Wade-O :p

First-off, I certainly appreciate the offer. I don't have a B33 motor to compare, but at least the head and barrell are completely different. The M23 has a bore of 82 mm (same as an M20) as opposed to the 85 mm bore of the B33. This is not to say that a B33 barrell and piston couldn't be installed or maybe even just a B33 piston (and give me an extra 20 cc's - waahoo!). I need to measure the motor/barrell to determine the wrist pin location/deck height. When I get into that, I may be contacitng you for some measurements.

Partly in order to clean up the "big pile in the corner of the living room" for my big birthday extravaganza and partly because it needed to be done, I have performed the first mock-up of my 1940 M23 Silver Star. I hesitate to call it a restoration since it will be rebuilt as a rider, but it will be mostly stock with a few nods toward useability/rideability and a few toward style and maybe not making this endeavor cost me a fortune (though I keep slipping on that).

This was a very educational experience. I got to fit some goodies that I've collected like the three badly worn fork links so I could at least get it upright. I managed to fit the repro 8" headlamp and the original brake lever....still missing a clutch lever - those things are very sought after. What became apparent pretty soon, though was that bot the front and rear fenders have a lot of problems. The front fender is an indian reproduction of an WM20 fender and it fits like a mumu on a bodybuilder....yea, it'll fit but it's just wrong. I've seen a few original WM20 pics and it appears that a lot of those fit that poorly as well. As for the rear, I think some panel beating will rectify the lack of clearance for both the upper and lower chainguards. Perhaps the toughest thing to deal with will be that the entire rear section of the frame is tweaked. That'll certainly take some doing.

I like this pic because it shows the unique for 1940 Lucas MT1130 taillight. This same unit was later used on the MG T-series in the 50's. The license plate is a repro that I'm just going to weld the light hole up on.

The other thing I'm working on is the crankshaft. I how have it disassembled and ready to receive a reconditioned big end and shorter rod. The shorter rod is necessary since original pistons are non-existent but since it's the same bore as the much more common M20, I can use a piston from one of those if I use a con rod from a 53-60 B31. The resultant deck height will give me 7.5:1 compression...about as much as anyone would want with an all-iron top end.

The original big-end bearing is between the flywheel halves...it's rusty, clapped out and the oil feed in it and the timing side flywheel were completely blocked. The new crankpin is sitting in the TS flywheel (right) which with new oversized rollers (available for Harleys) will be fitted to the new (used) rod. The race in the rod will be honed to fit the new rollers.

To say the flywheels were rough is an understatement. They looked like they had been beaten to within an inch of their lives. In addition to the beatings on the OD and faces, the mating faces for the crankpin nuts looked like they had been plowed with a cold chisel.

So the first step was to turn the OD and faces of the flywheels down to where they were round and flat again.

So they could be trued up, now with good surfaces.

The next step were the crankpin nut faces. The highly eccentric turning had to be done at very low speed and with a boring bar to get inside the drive shaft.

Next: salvaging the threads on the shaft ends and welding up the crankcases, cylinder and head.

Wow...I'm just now seeing that it's been almost two years since I posted. Progress has been slow as other projects have gotten in the way, but

Tank is plated and painted as are the rims (not shown)paint by Don Roe

The crank is assembled and trued with a reconditioned big end bearing and short rod for use with M20 piston. I don't have a pic of the modified piston but I found that it needs to be clearanced for the flywheels, as it is a very tall piston. No problem, a bit of bandsaw work and sanding did the trick.

The sump plate area was welded up with a new plate to replace multiple previous botched repairs. The welding was done by Tom at Carolina Custom Powdercoat.

One of the bosses had also been broken off on the other crankcase half so Tom built up some aluminum.

After machining the sump region. Just a little bit of sanding from here.

And a mockup of the finished cases with bored and painted barrel and head.

Next: installing the crankshaft, making valve guides (they are a very odd size), collecting all of the fasteners I can find and taking them to be cad plated, building the wheels and straightening the frame. Still no front mudguard...

I forgot to grab it when I was at his house. Still, it's going to need a little bit of metalwork to fit and a lot to make it into that valanced fender...I guess I should have clarified by saying "not done yet"

The M20 piston, originally tall with a straight skirt is now clearanced for the shorter rod now looks something more like a normal piston:

The cases and the crank now being done, I wanted to start on the ancillary stuff like cams and lifters. The cams were dirty but it turns out that what only looked like filth were actually deep corrosion pits:

The lifters were the same...pretty much trash. Discouraged, I moved on to the gearbox. I already knew that the actuating lever boss was broken:

but I had a spare wartime box in pretty good condition that I could use the outer cover from. The boss is a little different on the later box, but I can make it work. Then, once I'd opened the box up, I found a bit of a crack in the inner cover, which you can see running almost vertical through the whole inner cover:

The cover was, in fact, broken all the way through and had been repaired by attaching a thin steel plate with multiple rivets. Inside the box, things weren't much better. Severely worn dogs and missing shims (Related??) and then, I found a crack in the main case:

Gordo, they are M20/B33 cams. I was fortunate enough to have found that a very rough M20 bottom end donated by a friend has good cams and lifters. And yes, welding will have to sort the some things, but I think I will use most of a WD M20 box that is in good shape for a replacement. Most things are the same except for the lack of a groove for the rubber boot on the clutch actuator boss.

Then, I thought I had found a casting that didn't need some sort of repair: The rocker box. Cleaned up and bead blasted, it sure is looking nice:

But the cleanup and bead blasting has revealed that my excitement was premature:

That will certainly have to be welded. A unique M23 casting...they're hard to come by.

I have visions of the bike at one point having a utility chair bolted to it used to haul logs and or ailing livestock in rural Iran...